LIQUID CRYSTAL DISPLAY DEVICE

• US 20150234224A1
• Filed: 11/07/2014
• Published: 08/20/2015
• Est. Priority Date: 02/18/2014
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: JANG, Chang-Soon, SHIM, YiSeop, HUH, Chul, KIM, Heera
• Granted Patent: US 9,465,259 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G02F 1/13394 spacers regularly patterned on the cell subtrate, e.g. walls, pillars G02F1/133377 takes precedence
• CPC Class Codes: G02F 1/13396 Spacers having different sizes
• CPC Class Codes: G02F 1/13398 Spacer materials; Spacer properties
• CPC Class Codes: H01L 27/1262 with a particular formation, treatment or coating of the substrate

Abstract

Provided is an LCD device including a first substrate, a second substrate, a liquid crystal layer, a main spacer, and a supplementary spacer. The liquid crystal layer is interposed between the first and second substrates. The main spacer makes contact with the first and second substrates. The supplementary spacer makes contact with one of the first and second substrates and is spaced apart from the other. A first area ratio defined by dividing the area of a first top surface by that of a first bottom surface of the main spacer may be smaller than a second area ratio defined by dividing the area of a second top surface by that of a second bottom surface of the supplementary spacer.

Claims

1. A liquid crystal display (LCD) device, comprising:

a first substrate having a plurality of pixels;

a second substrate facing the first substrate;

a liquid crystal layer interposed between the first and second substrates;

a main spacer disposed between the first and second substrates and making contact with the first and second substrates, and the main spacer having a first top surface and a first bottom surface having an area larger than that of the first top surface; and

a supplementary spacer disposed between the first and second substrates to make contact with one of the first and second substrates and be spaced apart from the other, and the supplementary spacer having a second top surface and a second bottom surface having an area larger than that of the second top surface,

wherein a first area ratio, which is defined by dividing the area of the first top surface by that of the first bottom surface, is smaller than a second area ratio, which is defined by dividing the area of the second top surface by that of the second bottom surface.

2. The device of claim 1, wherein the supplementary spacer is harder than the main spacer.

3. The device of claim 1, wherein the main spacer has a first side surface connecting the first top surface to the first bottom surface, and the supplementary spacer has a second side surface connecting the second top surface to the second bottom surface,

wherein the first side surface has a curvature radius that is smaller than that of the second side surface.

4. The device of claim 3, wherein the first area ratio ranges from about 38% to about 44%, and the second area ratio ranges from about 45% to about 52%.

5. The device of claim 1, wherein the first and second bottom surfaces are in contact with the first substrate, the first top surface is in contact with the second substrate, and the second top surface is spaced apart from the second substrate.

6. The device of claim 1, wherein the supplementary spacer has a thickness that is smaller than that of the main spacer.

7. The device of claim 1, wherein each of the main and supplementary spacers is provided in plural numbers on a non-pixel region of the first substrate, and the number of the main spacers is smaller than the number of the supplementary spacers.

8. A method of fabricating a liquid crystal display device, comprising:

forming a first substrate having a plurality of pixels;

forming a second substrate;

forming a liquid crystal layer between the first and second substrates; and

forming a main spacer and a supplementary spacer between the first and second substrates,

wherein the main spacer is formed to make contact with the first and second substrates and have a first area ratio defined by dividing an area of a top surface thereof by an area of a bottom surface thereof,

wherein the supplementary spacer is formed to make contact with one of the first and second substrates and be spaced apart from the other and have a second area ratio defined by dividing an area of a top surface thereof by an area of a bottom surface thereof, and

wherein the first area ratio is smaller than the second area ratio.

9. The method of claim 8, wherein the main spacer is formed to be softer than the supplementary spacer.

10. The method of claim 8, wherein the forming of the main and supplementary spacers comprises:

forming a photosensitive film on one of the first and second substrates;

irradiating first and second regions of the photosensitive film with light; and

developing the photosensitive film,

wherein the main and supplementary spacers are formed on the first and second regions, respectively, after the developing of the photosensitive film,

the first region is irradiated with light of a first intensity, and the second region is irradiated with light of a second intensity different from the first intensity.

11. The method of claim 10 wherein the photosensitive film is of a positive type, and the first intensity is lower than the second intensity.

12. The method of claim 11, wherein the main spacer is formed to be softer than the supplementary spacer.

13. The method of claim 8, wherein the supplementary spacer is formed to be thinner than the main spacer.

14. The method of claim 8, wherein the main spacer has a first side surface connecting the top and bottom surfaces thereof, and the supplementary spacer has a second side surface connecting the top and bottom surfaces thereof,

wherein the first side surface is formed to have a curvature radius that is smaller than that of the second side surface.

15. The method of claim 10, wherein the developing of the photosensitive film comprises forming first and second preliminary spacers on the first and second regions, respectively, and

the forming of the main and supplementary spacers further comprises reflowing the first and second preliminary spacers using a heat.

16. The method of claim 15, wherein the reflowing of the first and second preliminary spacers is performed to define the first and second area ratios.